extruder drive gear issues in printrbot metal plus

Is your extruder stepper motor heating up? The rule of thumb (finger?) is you should be able to hold your finger on the motor for 6 to 10 seconds - steppers can run pretty hot (google your motor's datasheet if you want to know more), but will loose power if they get too hot. You may need to lower your extruder stepper power to prevent the motor from overheating and losing power. Since you don't seem to be grinding holes in the side of your plastic it's likely not the extruder gear heating and softening the filament, but at least keep that in mind. I'd lean towards the motor current being set to high = while there's topics here on how to adjust it basically lower it in, say, 10% increments until the problem goes away. I'm not a fan of determining the minimum value you can use as you'll be limiting how fast you can extrude (and therefor print) but too high will lead to overheating and be just as bad.

There's extruder flow volume test gcode in this topic (the buffered issued RJ mentions shouldn't matter for a quick test...) that you can consider using. Your video looks like a ceramic UBIS, so if you try it post the results in that topic,

It looks like you're printing the first couple solid layers in your video. Depending on how accurately you've set your Z offset, the extruder might be trying to extrude plastic when the nozzle is blocked by previous layers of 100% infill which have too much plastic accumulation from the 1st layer squish. If it still clicks a few layers into the sparse infill though, you have a problem.